1. Field of Invention
The present invention relates generally to a liquid dispenser, and more particularly to an automatic liquid dispenser useful in a variety of applications in which a consistent volume of liquid needs to be dispensed at periodic time intervals.
2. Description of Prior Art
Dispensing liquids on a periodic basis is a common task around the home, workplace, or laboratory. Typical applications that require liquid to be dispensed in a controlled fashion include plant watering/feeding, fertilizing, air freshening, drain cleaning, toilet bowl cleaning, pet watering, medicating, lubricating, humidifying and fumigating.
Expanding on the plant watering/feeding example, house plants are a popular way to create a pleasant, healthy environment in the home or office. However, if there are many plants, this entails a great deal of time, effort and inconvenience. Too little or too much water can injure or kill a plant. Also, many plants do best when the roots are allowed to dry between waterings. Watering should therefore be done on a regular basis using a correct amount of water at the appropriate interval. Also, if the plant caretaker is absent for any extended period of time, arrangements must be made for watering. It is expensive to pay an interim caretaker, and could possibly cause a security problem as well. Therefore, an automatic watering/feeding system would be desirable.
Although various automatic watering systems are known, none are widely used in home and office. It is common to use systems with small orifices or restrictors which drip water continuously onto the plant. Such systems are typically used in a nursery or garden, where plants are grouped closely together, and water can be supplied from a pressurized source. Since it is necessary to interconnect each plant with a tube or pipe, these systems are impractical or undesirable for the typical home or office where plants are spread out or moved randomly. Further, these types of systems are relatively expensive. Pressurized systems and some gravity feed systems from an elevated reservoir are sometimes used but this also includes interconnected tubing and is therefore impractical for most watering requirements in the home or office.
Other methods used to water individual plants, sometimes used by vacationers, may include moving the plants to a sink, for example, and setting them in a shallow level of water, thus soaking the roots continuously for the entire period of absence. This method is impractical where the plants are too numerous or too big to move. It also is harmful to those plants which require roots to dry out between waterings. Too much water can lead to mold, for example, which can kill the plant. Yet another method used includes setting a container of water next to or above the plant and extending a wetted wick from the container to the plant. Capillary action draws water gradually and continually from the container to the plant. This method has several drawbacks. While the flow is continual, the rate of flow varies with the level of water in the container. As the level drops, the flow rate slows. Also, since the flow is continual, there is the possibility of damage to the plant due to over-soaking of the roots.